The present disclosure relates to capacitor structures, and particularly to capacitor structures having interdigitated conductive lines, and methods of manufacturing the same.
Back-end-of-line (BEOL) metal capacitors are important devices for foundry and server applications. BEOL metal capacitors have electrical properties that are beneficial to analog circuits. For example, BEOL metal capacitors provide good mismatch tolerance, low parasitic capacitance, and low voltage and temperature coefficients of capacitance.
BEOL metal capacitors employ conductive lines embedded in a dielectric material layer. The conductive lines are formed as metal lines filling line trenches in the dielectric material layer at the same time when other metal lines for metal interconnect structures are formed. The distance between the conductive lines is typically a critical dimension, i.e., the smallest dimension that may be printed by lithographic methods. Because such BEOL metal capacitors are formed in the same processing steps that are employed to form other metal interconnect structures, such BEOL metal capacitors may be manufactured without incurring an additional processing cost.
As semiconductor devices scale and the pitch of metal lines shrink, new patterning constraints are introduced. These constraints can often make scaling old designs into new technologies impossible. Therefore, new and flexible designs for BEOL metal capacitors are desired.